Do you have a wind sensor installed on your awning? I wonder if the vibration of opening the awning could be setting off the wind sensor and causing the awning to close. My awning will sometimes close when I don't want it to, like when I am cleaning it. Trying to avoid this, I removed the sensor while I cleaned the awning and I learned that if the sensor is removed, there is a timer in the controller that will retract the awning automatically after several minutes. The wind sensor is a good idea, but I don't always like it when things have a mind of their own.
JJ